Sunscreen compositions

ABSTRACT

The present invention provides a method of producing a composition, suitable for use in pharmaceutical or cosmetic compositions, comprising a micronised insoluble organic UV absorber, which method comprises grinding the insoluble organic UV absorber, in coarse particle form, in a grinding apparatus, in the presence of 0.1 to 30% by weight of an alkyl polyglucoside having the formula C n  H 2n+1  O(C 6  H 10  O 5 ) x  H, in which n is an integer ranging from 8 to 16 and x is the mean polymerization level of the glucoside moiety (C 6  H 10  O 5 ) and ranges from 1.4 to 1.6, or an ester thereof.

The present invention relates to a method for producing new formulationsof UV absorbers and to their use in sunscreen compositions which, inturn, are useful, in particular, for the protection of human skin.

It has long been known that prolonged exposure to that UV radiationwhich reaches the surface of the earth can lead to the formation oferythemas or light dermatoses, as well as to an increased incidence ofskin cancers or accelerated skin aging.

Various sunscreen formulations have been proposed which include amaterial which is intended to counteract UV radiation, therebyinhibiting the said undesired effects on the skin.

A great number of compounds has been proposed for use as UV protectantsin sunscreen formulations, especially soluble organic UV absorbers andinsoluble micronised inorganic compounds, in particular zinc oxide andtitanium dioxide.

With respect to the use in sunscreen formulations of soluble organic UVabsorbers, they have the disadvantages that their effectiveness as UVprotectants in terms of SPF (Sun Protection Factor) in a sunscreenformulation is often too low for commercial purposes; as a result oftheir solubility, they exhibit relatively high allergenic potential; andthat as a result of intrinsic photochemical lability, the duration ofthe protective effect is often too low.

The high specific weight of insoluble inorganic compounds, such as zincoxide and titanium dioxide leads to a reduced stability of formulationscontaining them. Moreover, such inorganic compounds have been claimed togenerate toxic radicals under the influence of light ("Redox Mechanismsin Heterogeneous Photocatalysis", Serpone et al, Electrochemistry inColloids and Dispersions, Editors Mackay and Texter, VCH PublishersInc., New York 1992).

Micronized, insoluble organic UV absorbers, when used in sunscreenformulations, provide excellent UV protection and have at least as highan SPF rating as corresponding sunscreen formulations containing a knowninorganic UV absorber. Unlike the latter UV absorbers, micronized,insoluble organic UV absorbers show no tendency, under the influence oflight, to generate radicals which could damage or sensitise human skin.

Accordingly, the present invention provides, as a first aspect, a methodof producing a composition, which is especially suitable for use inpharmaceutical or cosmetic applications, comprising a micronisedinsoluble organic UV absorber, which method comprises grinding theinsoluble organic UV absorber, in coarse particle form, in a grindingapparatus, in the presence of 1 to 50%, preferably 5 to 40% by weight,based on the micronised insoluble organic UV absorber, of an alkylpolyglucoside having the formula C_(n) H_(2n+1) O(C₆ H₁₀ O₅)_(x) H, inwhich n is an integer ranging from 8 to 16 and x is the meanpolymerisation level of the glucoside moiety (C₆ H₁₀ O₅) and ranges from1.4 to 1.6, or an ester thereof.

The insoluble organic UV absorber may be, e.g., an oxanilide, atriazine, a triazole, a vinyl group-containing amide, a cinnamic acidamide or a sulfonated benzimidazole UV absorber.

One preferred class of oxanilide UV absorbers is that having theformula: ##STR1## in which R₁ and R₂, independently, are C₁ -C₁₈ alkylor C₁ -C₁₈ alkoxy. A preferred compound of formula (1) isN-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethanediamide.

A preferred class of triazine compounds is that having the formula:##STR2## in which R₃, R₄ and R₅, independently, are H, OH, C₁ -C₁₈alkoxy, NH₂, NH--R₆ or N(R₆)₂ in which R₆ is C₁ -C₁₈ alkyl, OR₆ in whichR₆ has its previous significance, phenyl, phenoxy or anilino, orpyrrole, in which the respective phenyl, phenoxy or anilino, or pyrrolomoieties are optionally substituted by one, two or three substitutentsselected from OH, carboxy, CO--NH₂, C₁ -C₁₈ alkyl or -alkoxy, C₁ -C₁₈carboxyalkyl, C₅ -C₈ cycloalkyl, a methylidenecamphor group, a group--(CH═CH)_(m) C(═O)--OR₆ in which m is 0 or 1 and R₆ has its previoussignificance, or a group ##STR3## or the corresponding alkali metal,ammonium, mono-, di- or tri-C₁ -C₄ alkylammonium, mono-, di- or tri-C₂-C₄ alkanolammonium salts, or the C₁ -C₁₈ alkyl esters thereof.

Preferred compounds of formula (2) are those having one of the formulae:##STR4## as well as2,4,6-tris(diisobutyl-4'-aminobenzalmalonate)-s-triazine and2,4-bis(diisobutyl-4-aminobenzalmalonate)-6-(4'-aminobenzylidenecamphor)-s-triazine.

Particularly preferred compounds of formula (2) are those having theformula: ##STR5## in which the individual radicals R₇ are the same ordifferent and each is hydrogen; an alkali metal; an ammonium groupN(R₈)₄ in which R₈ is hydrogen or an organic radical; C₁ -C₂₀ alkyl; ora polyoxyethylene radical which contains from 1 to 10 ethylene oxideunits and the terminal OH group of which may be etherified by a C₁ -C₃alcohol.

In relation to the compounds of formula (30), when R₇ is an alkali metalit is preferably potassium or, especially sodium; when R₇ is a groupN(R₈)₄ in which R₈ has its previous significance, it is preferably amono-, di- or tri-C₁ -C₄ alkylammonium salt, a mono-, di- or tri-C₂ -C₄alkanolammonium salt or a C₁ -C₂₀ alkyl ester thereof; when R₈ is a C₁-C₂₀ alkyl group, it is preferably a C₆ -C₁₂ alkyl group, morepreferably a C₈ -C₉ alkyl group, especially the 3,5,5-trimethylpentylgroup or, most particularly, the 2-ethylhexyl group; and when R₈ ispolyoxyethylene group, this preferably contains from 2-6 ethylene oxideunits.

One preferred class of triazole insoluble organic UV absorbers is thathaving the formula: ##STR6## in which T₁ is C₁ -C₁₈ alkyl or,preferably, hydrogen; and T₂ is C₁ -C₁₈ alkyl, optionally substituted byphenyl, preferably α,α-dimethylbenzyl.

A further preferred class of triazole insoluble organic UV absorbers isthat having the formula: ##STR7## in which T₂ has its previoussignificance.

A still further preferred class of triazole insoluble organic UVabsorbers is that having the formula: ##STR8## in which T₂ has itsprevious significance and is preferably t-butyl.

A preferred class of vinyl group-containing amide insoluble organic UVabsorbers is that having the formula:

    R.sub.9 --(Y).sub.m --CO--C(R.sub.10)═C(R.sub.11)--N(R.sub.12)(R.sub.13)(34)

in which R₉ is C₁ -C₁₈ alkyl, preferably C₁ -C₅ alkyl, or phenyloptionally substituted by one, two or three substituents selected fromOH, C₁ -C₁₈ alkyl, C₁ -C₁₈ alkoxy or CO--OR₆ in which R₆ has itsprevious significance; R₁₀, R₁₁, R₁₂ and R₁₃ are the same or differentand each is C₁ -C₁₈ alkyl, preferably C₁ -C₅ alkyl, or hydrogen; Y is Nor O; and m has its previous significance.

Preferred compounds of formula (34) are 4-octyl-3-penten-2-one,ethyl-3-octylamino-2-butenoate, 3-octylamino-1-phenyl-2-buten-1-one and3-dodecylamino-1-phenyl-2-buten-1-one.

A preferred class of cinnamic acid amide insoluble organic UV absorbersis that having the formula: ##STR9## in which R₁₄ is hydroxy or C₁ -C₄alkoxy, preferably methoxy or ethoxy; R₁₅ is hydrogen or C₁ -C₄ alkyl,preferably methyl or ethyl; and R₁₆ is --(CONH)_(m) -phenyl in which mhas its previous significance and the phenyl group is optionallysubstituted by one, two or three substituents selected from OH, C₁ -C₁₈alkyl, C₁ -C₁₈ alkoxy or CO--OR₆ in which R₆ has its previoussignificance. Preferably R₁₆ is phenyl, 4-methoxyphenyl or thephenylaminocarbonyl group.

A preferred class of sulfonated benzimidazole insoluble organic UVabsorbers is that having the formula: ##STR10## in which M is hydrogenor an alkali metal, preferably sodium, an alkaline earth metal, such asmagnesium or calcium, or zinc.

In the compounds of formula (1) to (35), C₁ -C₁₈ alkyl groups may bemethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl,n-amyl, n-hexyl, n-heptyl, n-octyl, isooctyl, n-nonyl, n-decyl,n-undecyl, n-dodecyl, tetradecyl, hexydecyl or octadecyl; and C₁ -C₁₈alkoxy groups include methoxy, ethoxy, propoxy, butoxy, n-hexoxy,n-heptoxy, n-octoxy, isooctoxy, n-nonoxy, n-decoxy, n-undecoxy,n-dodecoxy, tetradecoxy, hexadecoxy or octadecoxy, methoxy and ethoxybeing preferred.

C₁ -C₁₈ carboxyalkyl includes carboxymethyl, carboxyethyl,carboxypropyl, carboxyisopropyl, carboxybutyl, carboxyisobutyl,carboxybutyl, carboxyamyl, carboxyhexyl, carboxyheptyl, carboxyoctyl,carboxyisooctyl, carboxynonyl, carboxydecyl, carboxyundecyl,carboxydodecyl, carboxytetradecyl, carboxyhexadecyl andcarboxyoctadecyl, carboxymethyl being preferred.

C₅ -C₈ cycloalkyl includes cyclopentyl, cyclohexyl and cyclooctyl.

The compounds of formula (1) to (35) are known. The compounds of formula(30) are described, together with their production, in U.S. Pat. No.4,617,390.

Although they are excellent sun screen agents per se, the insolubleorganic UV absorbers suffer from the drawback that, to date, it hasproved difficult to formulate them in order to achieve a high SPF inhuman sun screen applications.

Surprisingly, it has now been found that the insoluble organic UVabsorbers, when micronised with a particular type of surfactant, namelyan alkyl polyglucoside, provide high SPF values. Moreover, suchformulations do not agglomerate and they remain in a dispersed form anddo not readily settle.

Preferably, the micronised insoluble organic UV absorber, producedaccording to the method of the present invention, has a mean particlesize in the range of from 0.01 to 2, more preferably from 0.02 to 1.5,especially from 0.05 to 1.0μ.

The grinding apparatus used to conduct the method of the presentinvention may be, e.g., a jet, ball, vibration or hammer mill,preferably a high speed stirring mill or impact mill, especially arotating ball mill, vibrating mill, tube mill or rod mill.

The alkyl polyglucoside may consist of a C₁ -C₁₂ ester of the compoundof formula C_(n) H_(2n+1) O(C₆ H₁₀ O₅)_(x) H, namely an ester formed byreacting a C₁ -C₁₂ acid, such formic, acetic, propionic, butyric,sulfosuccinic, citric or tartaric acid, with one or more free OH groupson the glucoside moiety (C₆ H₁₀ O₅).

The micronised formulation of a insoluble organic UV absorber, producedaccording to the method of the present invention may be used togetherwith one or more further UV absorbers, such as soluble organic UVabsorbers, insoluble inorganic UV absorbers and/or melanine, which areconventionally used in cosmetic compositions for the protection of humanskin against UV radiation. The use of such combinations of activeingredients may lead to synergistic effects.

As already indicated, the composition produced according to the methodof the present invention is particularly suitable for use in a sunscreenformulation.

Accordingly, the present invention also provides a sunscreen compositioncomprising a) 0.1 to 15%, preferably 0.5 to 10% by weight, based on thetotal composition of a micronised formulation of an insoluble organic UVabsorber, produced according to the method of the present invention; andoptionally b) a cosmetically acceptable carrier.

The sunscreen composition of the present invention may be produced byphysically blending the micronised formulation of an insoluble organicUV absorber and carrier components by any conventional method, e.g. bysimply stirring the two materials together. In a preferred procedure, amixture of the coarse, insoluble organic UV absorber, the alkylpolyglucoside grinding aid, and the milling bodies are ground until thecoarse, insoluble organic UV absorber has been converted into micronisedform, as described earlier in relation to the production of themicronised insoluble organic UV absorber. After filtering off themilling bodies, e.g. quartz sand, glass balls or zirconium silicateballs, the filtrate, consisting of the micronised insoluble organic UVabsorber and grinding aid components, may be blended with a cosmeticallycompatible carrier.

The sunscreen composition of the invention may be formulated as awater-in oil or an oil-in-water dispersion, an oil or oil-alcohollotion, a vesicular dispersion of an ionic or nonionic amphiphiliclipid, a gel, a solid stick or an aerosol formulation.

When formulated as a water-in oil or an oil-in-water dispersion, theoptional cosmetically acceptable carrier preferably comprises 5 to 50%of an oil phase, 5 to 20% of an emulsifier and 30 to 90% of water, eachby weight based on the total weight of the carrier.

The oil phase may comprise any oil conventionally used in cosmeticformulations, e.g., one or more of a hydrocarbon oil, a wax, a naturaloil, a silicone oil, a fatty acid ester or a fatty alcohol. Preferredmono- or polyols are ethanol, isopropanol, propylene glycol, hexyleneglycol, glycerine and sorbitol.

The emulsifier also may comprise any emulsifier conventionally used incosmetic formulations, e.g., one or more of an ethoxylated ester of anatural oil derivative such as a polyethoxylated ester of hydrogenatedcastor oil; a silicone oil emulsifier such as a silicone polyol; anoptionally ethoxylated fatty acid soap; an ethoxylated fatty alcohol; anoptionally ethoxylated sorbitan ester; an ethoxylated fatty acid; or anethoxylated glyceride.

The sunscreen composition of the invention may also comprise furthercomponents which are known to perform a useful function in a sunscreencomposition. Examples of such further components include, e.g.,emollients, skin moisturisers, skin tanning accelerators, antioxidants,emulsion stabilisers, thickening agents such as xanthan,moisture-retention agents such as glycerine, film formers,preservatives, perfumes and colourants.

The sunscreen composition of the invention provides excellent protectionof the human against the damaging effects of sunlight, while permittingsafe tanning of the skin. Moreover, the sunscreen composition of theinvention has a skin waterproofing effect.

The following Examples further illustrate the present invention.

EXAMPLE 1 30 g of2,4,6-trianilino-p-(carbo-2'-ethylhexyl-1'-oxy)-1,3,5-triazine havingthe formula: ##STR11## are ground in a 200 ml grinding container at astirring speed of 8 m/s in a Drais bead mill in the presence of 12 g ofa C₈ -C₁₆ fatty alcohol polyglucoside and 300 g of zirconium silicategrinding aids (diameter 0.6-0.8 mm), over 15 minutes, with watercooling. The grinding aids are centrifuged off and the mean particlesize of the remaining dispersion product is found to be 1.06μ (measuredon a Malvern Mastersizer).

5 g of the resulting dispersion are then formulated with 0.25 g NaCl,0.25 g of a polydimethylsiloxane de-foamer, 13.25 g of water and 6.25 gof a thickener which contains, per litre, 16 g imidazolidinyl urea, 24 gof a mixture of methyl-, ethyl-, i-butyl- and n-butyl esters of4-hydroxybenzoic acid in phenoxyethanol, 40 g xanthan gum and 940 gwater.

The resulting lotion formulation is composed of:

10.0% 2,4,6-trianilino-p-(carbo-2'-ethylhexyl-1'-oxy)-1,3,5-triazine;

8.0% C₈ -C₁₆ fatty alcohol polyglucoside;

78.5% water;

1.0% de-foamer;

1.0% NaCl;

0.5% xanthan gum;

0.5% imidazolidinyl urea; and

0.6% mixed esters of 4-hydroxybenzoic acid.

The lotion has an average SPF (measured on an SPF analyzer/Optometricsaccording to DIN 67501) of 13.2.

EXAMPLE 2

Using an analogous procedure to that described in Example 1 but applyinga grinding time of 30 minutes, a formulation is obtained having a meanparticle size of 0.9μ (measured on a Malvern Mastersizer) and an averageSPF of 19.5.

EXAMPLE 3

Using an analogous procedure to that described in Example 1 but applyinga grinding time of 45 minutes, a formulation is obtained having a meanparticle size of 0.88μ (measured on a Malvern Mastersizer) and anaverage SPF of 22.8.

EXAMPLE 4

Using an analogous procedure to that described in Example 1 but applyinga grinding time of 80 minutes, a formulation is obtained having a meanparticle size of 0.73μ (measured on a Malvern Mastersizer) and anaverage SPF of 33.7.

The dependence of SPF on the level of micronisation is clearly apparentfrom the data in Examples 1 to 4.

EXAMPLE 5

Using the procedure described in Example 1, but replacing the2,4,6-trianilino-p-(carbo-2'-ethylhexyl-1'-oxy)-1,3,5-triazine usedtherein by the compound having the formula: ##STR12## there is obtaineda lotion formulation which is composed of: 10.0% compound (102);

4.0% C₈ -C₁₆ fatty alcohol polyglucoside;

82.5% water;

1.0% de-foamer;

1.0% NaCl;

0.5% xanthan gum;

0.5% imidazolidinyl urea; and

0.6% mixed esters of 4-hydroxybenzoic acid.

The lotion has an average SPF (measured on an SPF analyzer/Optometricsaccording to DIN 67501) of 18.7 at a particle size of 0.22μ.

Similar results are obtained using a lotion formulation which iscomposed of:

10.0% compound (102);

4.0% C₈ -C₁₆ fatty alcohol polyglucoside;

71.7% water;

1.0% de-foamer;

1.0% propyleneglycolstearate;

5% paraffin oil;

1.5% stearic acid;

0.4% cetyl/stearyl alcohol;

0.1% propyl ester of 4-hydroxybenzoic acid;

0.1% methyl ester of 4-hydroxybenzoic acid;

4.0% glycerine;

0.1% polyacrylic acid;

0.8% triethanolamine; and

0.5% xanthan gum.

EXAMPLE 6

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR13## there is obtained a lotion formulation which has an averageSPF (measured on an SPF analyzer/Optometrics according to DIN 67501) of31 at a particle size of 0.29μ.

EXAMPLE 7

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR14## there is obtained a lotion formulation which has an averageSPF (measured on an SPF analyzer/Optometrics according to DIN 67501) of17.5 at a particle size of 0.44μ.

EXAMPLE 8

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR15## there is obtained a lotion formulation which has an averageSPF (measured on an SPF analyzer/Optometrics according to DIN 67501) of20.4 at a particle size of 0.4μ.

EXAMPLE 9

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR16## there is obtained a lotion formulation which has an averageSPF (measured on an SPF analyzer/Optometrics according to DIN 67501) of15.2 at a particle size of 0.32μ.

Similar results are obtained when the acidic compound of formula (106)is replaced by an alkaline earth salt thereof, such as the magnesium orcalcium salt, or by the zinc salt thereof.

EXAMPLE 10

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR17## there is obtained a lotion formulation which has an averageSPF (measured on an SPF analyzer/Optometrics according to DIN 67501) of23.3 at a particle size of 0.43μ.

EXAMPLE 11

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR18## there is obtained a lotion formulation which has an averageSPF (measured on an SPF analyzer/Optometrics according to DIN 67501) of5.6 at a particle size of 0.4μ.

Similar results are obtained when the acidic compound of formula (108)is replaced by an alkaline earth salt thereof, such as the magnesium orcalcium salt, or by the zinc salt thereof.

EXAMPLE 12

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR19## there is obtained a lotion formulation which has an averageSPF (measured on an SPF analyzer/Optometrics according to DIN 67501) of17.0 at a particle size of 0.31μ.

EXAMPLE 13

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR20## there is obtained a lotion formulation.

EXAMPLE 14

Using the procedure described in Example 5, but replacing the compoundof formula (102) used therein by the compound having the formula:##STR21## there is obtained a lotion formulation.

We claim:
 1. A method of producing a composition, suitable for use inpharmaceutical or cosmetic compositions, comprising a micronisedinsoluble organic UV absorber, which method comprises grinding theinsoluble organic UV absorber, in coarse particle form, in a grindingapparatus, in the presence of 1 to 50% by weight of an alkylpolyglucoside having the formula C_(n) H_(2n+1) O(C₆ H₁₀ O₅)_(x) H, inwhich n is an integer ranging from 8 to 16 and x is the meanpolymerisation level of the glucoside moiety (C₆ H₁₀ O₅) and ranges from1.4 to 1.6, or an ester thereof.
 2. A method according to claim 1 inwhich the amount of alkyl polyglucoside is from 5 to 40% by weight.
 3. Amethod according to claim 1 in which the insoluble organic UV absorberis an oxanilide, a triazine, a triazole, a vinyl group-containing amide,a cinnamic acid amide or a sulfonated benzimidazole UV absorber.
 4. Amethod according to claim 3 in which the oxanilide UV absorber has theformula: ##STR22## in which R₁ and R₂, independently, are C₁ -C₁₈ alkylor C₁ -C₁₈ alkoxy.
 5. A method according to claim 4 in which thecompound of formula (1) isN-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-ethanediamide.
 6. A methodaccording to claim 3 in which the triazine UV absorber has the formula:##STR23## in which R₃, R₄ and R₅, independently, are H, OH, C₁ -C₁₈alkoxy, NH₂, NH--R₆ or N(R₆)₂ in which R₆ is C₁ -C₁₈ alkyl, OR₆ in whichR₆ has its previous significance, phenyl, phenoxy or anilino, orpyrrolo, in which the respective phenyl, phenoxy or anilino, or pyrrolomoieties are optionally substituted by one, two or three substitutentsselected from OH, carboxy, CO--NH₂, C₁ -C₁₈ alkyl or -alkoxy, C₁ -C₁₈carboxyalkyl, C₅ -C₈ cycloalkyl, a methylidenecamphor group, a group--(CH═CH)_(m) C(═O)--OR₆ in which m is 0 or 1 and R₆ has its previoussignificance, or a group ##STR24## or the corresponding alkali metal,ammonium, mono-, di- or tri-C₁ -C₄ alkylammonium, mono-, di- or tri-C₂-C₄ alkanolammonium salts, or the C₁ -C₁₈ alkyl esters thereof.
 7. Amethod according to claim 6 in which the triazine compound is of theformula: ##STR25## or is2,4,6-tris(diisobutyl-4'-aminobenzalmalonate)-s-triazine or2,4-bis(diisobutyl-4-aminobenzalmalonate)-6-(4'-aminobenzylidenecamphor)-s-triazine.8. A method according to claim 6 in which the triazine compound has theformula: ##STR26## in which the individual radicals R₇ are the same ordifferent and each is hydrogen; an alkali metal; an ammonium groupN(R₈)₄ in which R₈ is hydrogen or an organic radical; C₁ -C₂₀ alkyl; ora polyoxyethylene radical which contains from 1 to 10 ethylene oxideunits and the terminal OH group of which may be etherified by a C₁ -C₃alcohol.
 9. A method according to claim 8 in which when R₇ is an alkalimetal it is potassium or sodium; when R₇ is a group N(R₈)₄ in which R₈is as defined in claim 8, it is a mono-, di- or tri-C₁ -C₄ alkylammoniumsalt, a mono-, di- or tri-C₂ -C₄ alkanolammonium salt or a C₁ -C₂₀ alkylester thereof; when R₈ is a C₁ -C₂₀ alkyl group, it is a C₆ -C₁₂ alkylgroup; and when R₈ is polyoxyethylene group, this contains from 2-6ethylene oxide units.
 10. A method according to claim 3 in which thetriazole organic UV absorber has the formula: ##STR27## in which T₁ isC₁ -C₁₈ alkyl or hydrogen; and T₂ is C₁ -C₁₈ alkyl, optionallysubstituted by phenyl.
 11. A method according to claim 10 in which T₂ isα,α-dimethylbenzyl.
 12. A method according to claim 3 in which thetriazole organic UV absorber has the formula: ##STR28## in which T₂ isC₁ -C₁₈ alkyl, optionally substituted by phenyl.
 13. A method accordingto claim 3 in which the triazole organic UV absorber has the formula:##STR29## in which T₂ is C₁ -C₁₈ alkyl, optionally substituted byphenyl.
 14. A method as defined in claim 13 in which T₂ is t-butyl. 15.A method according to claim 3 in which the vinyl group-containing amideorganic UV absorber has the formula:

    R.sub.9 --(Y).sub.m --CO--C(R.sub.10)═C(R.sub.11)--N(R.sub.12)(R.sub.13)(34)

in which R₉ is C₁ -C₁₈ alkyl or phenyl optionally substituted by one,two or three substituents selected from OH, C₁ -C₁₈ alkyl, C₁ -C₁₈alkoxy or CO--OR₆ in which R₆ is C₁ -C₁₈ alkyl; R₁₀, R₁₁, R₁₂ and R₁₃are the same or different and each is C₁ -C₁₈ alkyl or hydrogen; Y is Nor O; and m is 0 or
 1. 16. A method according to claim 15 in which thecompound of formula (34) is 4-octyl-3-penten-2-one,ethyl-3-octylamino-2-butenoate, 3-octylamino-1-phenyl-2-buten-1-one or3-dodecylamino-1-phenyl-2-buten-1-one.
 17. A method according to claim 3in which the cinnamic acid amide organic UV absorber has the formula:##STR30## in which R₁₄ is hydroxy or C₁ -C₄ alkoxy; R₁₅ is hydrogen orC₁ -C₄ alkyl; and R₁₆ is --(CONH)_(m) -phenyl in which m is 0 or 1 andthe phenyl group is optionally substituted by one, two or threesubstituents selected from OH, C₁ -C₁₈ alkyl, C_(1-C) ₁₈ alkoxy orCO--OR₆ in which R₆ is C₁ -C₁₈ alkyl.
 18. A method according to claim 17in which R₁₆ is phenyl, 4-methoxyphenyl or the phenylaminocarbonylgroup.
 19. A method according to claim 3 in which the sulfonatedbenzimidazole organic UV absorber has the formula: ##STR31## in which Mis hydrogen or an alkali metal, an alkaline earth metal or zinc.
 20. Amethod according to claim 1 in which the alkyl polyglucoside consists ofa C₁ -C₁₂ ester of the compound of formula C_(n) H_(2n+1) O(C₆ H₁₀O₅)_(x) H.
 21. A method according to claim 20 in which the ester isformed by reacting formic, acetic, propionic, butyric, sulfosuccinic,citric or tartaric acid, with one or more free OH groups on theglucoside moiety (C₆ H₁₀ O₅).
 22. A method according claim 1 in whichthe micronized insoluble organic UV absorber so obtained has a meanparticle size in the range of from 0.01 to 2.0μ.
 23. A method accordingclaim 1 in which the micronized insoluble organic UV absorber has beenproduced by grinding it, in coarse particulate form, in a grindingapparatus, until the insoluble organic UV absorber has been convertedinto micronised form.
 24. A method according to claim 23 in which thegrinding apparatus is a jet, ball, vibration or hammer mill.
 25. Acomposition comprising a micronised insoluble organic UV absorberproduced by the method claimed in claim
 1. 26. A sunscreen compositioncomprising a) 0.1 to 15% by weight of a micronized insoluble organic UVabsorber composition according to claim 25; and optionally b) acosmetically acceptable carrier.
 27. A sunscreen composition accordingto claim 26 comprising a) 0.5 to 10% by weight of the micronisedinsoluble organic UV absorber composition; and optionally b) acosmetically acceptable carrier.
 28. A composition according to claim 26in which the micronized insoluble organic UV absorber is an oxanilide atriazine, a triazole, a vinyl group-containing amide, a cinnamic acidamide or a sulfonated benzimidazole UV absorber.
 29. A compositionaccording to claims 26 in which the micronized insoluble organic UVabsorber has a mean particle size in the range of form 0.01 to 2.0μ. 30.A composition according to claim 26 in which the micronized insolubleorganic UV absorber has been produced by grinding it, in coarseparticulate form, in a grinding apparatus, until the insoluble organicUV absorber has been converted into micronised form.
 31. A compositionaccording to claim 30 in which the grinding apparatus is a jet, ball,vibration or hammer mill.
 32. A composition according to claim 26 inwhich the micronized insoluble organic UV absorber is used together withone or more further UV absorbers which are conventionally used incosmetic compositions for the protection of human skin against UVradiation.
 33. A sunscreen composition according to claim 26 which isformulated as a water-in oil or an oil-in-water dispersion, an oil oroil-alcohol lotion, a vesicular dispersion of an ionic or nonionicamphiphilic lipid, an oil-alcohol or alcohol gel, a solid stick or anaerosol formulation.
 34. A sunscreen composition according to claim 33which is formulated as a water-in oil or an oil-in-water dispersion andcomponent b) comprises 5 to 50% of an oil phase, 5 to 20% of anemulsifier and 30 to 90% of water, each by weight based on the totalweight of the carrier.
 35. A sunscreen composition according to claim 34in which the oil phase comprises one or more of a hydrocarbon oil, awax, a natural oil, a silicone oil, a fatty acid ester or a fattyalcohol.
 36. A sunscreen composition according to claim 34 in which theemulsifier comprises one or more of an ethoxylated ester of a naturaloil derivative; a silicone oil emulsifier; an optionally ethoxylatedfatty acid soap; an ethoxylated fatty alcohol; an optionally ethoxylatedsorbitan ester; an ethoxylated fatty acid; or an ethoxylated glyceride.37. A sunscreen composition according to claim 36 in which theethoxylated ester of a natural oil derivative is a polyethoxylated esterof hydrogenated castor oil; and the silicone oil emulsifier is siliconepolyol.
 38. A sunscreen composition according to claim 26 in which thesunscreen composition also comprises one or more further componentsselected from the group consisting of emollients, skin moisturisers,skin tanning accelerators, antioxidants, emulsion stabilisers,thickening agents, moisture retention agents, film formers,preservatives, perfumes and colourants.